I have a small web application which is running well on my local machine but once I deploy my site to the server, all the other buttons click events are working except for one button event which is not firing:

Why on earth does your proc return the password instead of comparing it in the DB ? An update panel means AJAX, have you looked at it in fiddler to see what is happening ? Are your other events also via AJAX ? Is ASP.NET AJAX installed on the server ? Have you looked at it in chrome for JS errors ?